Experimental work on cold, trapped metastable noble gases is reviewed. The aspects which
distinguish work with these atoms from the large body of work on cold, trapped atoms in …

The current status of bound state quantum electrodynamics calculations of transition
energies for few-electron ions is reviewed. Evaluation of one and two body QED correction …

1.1. Background This article reports work carried out under the auspices of the Committee
on Data for Science and Technology (CODATA) Task Group on Fundamental Constants. 1 It …

We critically examine the current status of theoretical calculations of the energies, the fine
structure, and the isotope shift of the lowest-lying states of helium, searching for unresolved …

Precision spectroscopy of simple atomic systems has refined our understanding of the
fundamental laws of quantum physics. In particular, helium spectroscopy has played a …

Increasing accuracy of the theory and experiment of the n= 2 P 3 fine structure of helium has
allowed for increasingly precise tests of quantum electrodynamics (QED), determinations of …

Agreement between theoretical calculations of atomic structure and spectroscopic
measurements is used to constrain possible contribution of exotic spin-dependent …

We report a calculation of the fine-structure splitting in light heliumlike atoms, which
accounts for all quantum electrodynamical effects up to order α 5 Ry. For the helium atom …

Improvements in both theory and frequency metrology of few-electron systems such as
hydrogen and helium have enabled increasingly sensitive tests of quantum …

The line center of a resonance is affected by the presence of neighboring resonances due to
quantum interference between the two resonant processes. Such shifts must be accounted …